Geobg kalischeb and heinz scheyeb



[Patented June 24,1930

UNIT D STATES PATENT; OFFICE GEORG KALISCHER. AND n mz scEEYEa, E, rRANxEoar-oN-rEE-Mm, AND' PAUL NAWIASKY mm mm. KRAUCH, or ILU'DWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNOBS 'ro GENERAL AmLmE woaxs, me, or NEW YORK, n. "2.,

' A coEroEArron or DELAWARE v coim'ENsArIon' rnonuc'rs on THE. BENZANTHRONE SERIES AND rnocEss or mAxmo SAME Ho Drawing. Application fi led June 17,1927, Serial 110.19%),629, and-in Germany June 28, 15126.

Our invention relates to new condensation products of the benzanthrone series of a hitherto unknown chemical constitution, which are obtained by treating Bz.1- nitro-2-methyl benzanthrone of the formula:

0| with acid condensing agents, such as fuming sulfuric acid, chlorosulfonic acid or a mixture of both or aluminium-chloride with-or without addition of an indifferent solventor diluent. y

The condensation products thus obtained .are when dry gre to black colored powders,

practically insolu le in organic solvents, soluble in concentrated sulfuric acid to an olive solution. They ield with an alkaline solution ,of hydrosul te a reddish colored vat and dye cotton therefrom greenish to bluish ey v to black shades of a very 'good fastness. hey

may also beused as intermediates for production of-other dy'estufi's.

We have further found that besides the aforesaid condensation products a byproduct of reaction is obtained, which can be easily the separated from the condensation product by heating the raw product with organic solvents. -The by-product is easily; soluble therein and may be'isolated by'crystallization or precipitation with suitable agents. According to its properties it seems to be the ,inner anhydride of the Bz.1-amino benzan- ''throne-P-carboxylic acid, which maybe saponified to the free acid by means of. alkaline .actm'g agents. In' consequence of these propcities the by-product may also be isolated by therein.

boiling the raw products of reaction with dilute caustic soda solutions. B acidifying the alkaline solutions, thus obtalned, and filtratlng from the insoluble condensation prod the following examples are given, the parts being by-weight and all temperatures in centlgrade degrees, but it'is understood,'that our invention'is not limited to the particular products or reacting conditions mentioned Example I parts of fuming sulfuric acid of and the solution is stirred for a short time-until the dyestufi' formation is finished. Themass .1s t

then diluted by adding at 1020 250 parts of sulfuric acid of 90%. The mass is poured on ice and the separated product 'of reaction is filtered. It may be freed from the above I i mentioned by-product and some impurities by boiling it with dilute caustic'soda solution: The neweompound-is practically insoluble in organic solvents soluble in concentrated sulfuric acid with an olive ,green color. -It forms with an alkaline solution of hydrosulfite a bluish red vat from which cotton is dyed .grey shades of a good fastness.

Example [I At about 5 to 0 10 parts of finely powdered Bz.1-nitro-2-methyl benzanthroneare jquickly introduced into av mixture of about 100 parts of fuming sulfuric acid of 70% and 50 parts of chlorosulfonic'acid and the mass is'st-irred for about hour at thesame temperature. Then it is poured" into much wafiltered and freed from the mineralacid by washing with water. The dyestufitlius obter and the separated product-of reaction is I 00 A 50 parts-of Bz.1-nitro-2-methyl benzanthrone are introduced at 10. in about 250 tained is similar in its properties to the prodprocess comprises treating BZ'l-nitrO-Q- m'eth- I I 7 net described in Example I. r p I ylbenzanthrone of the formula For purifying (the dyestufi is extracted with much glacial acetic acid until no more substance dissolves. From the concentrated glacial acetic .acid Solution the dissolved by- 0:

product of the reaction separates partly as a brownish precipitate; the separation is completed b adding water. The newcom- 10 pound may recr stallize'd from nitroben- 1 zene inlittle crysta s, soluble in concentrated m o sulfuric acid with a green'color and melting i at 320. It dissolves to a small degree in coldz h acld condensing agents caustic soda solution with a green color and 3- Process for producing new condensatlon' 15 with a blue color in presence of a little pyri- Products h b n an P T .W so dine. By boiling the product, which is asprocess comprlsestreatmgBz.1-n1tro-2-methsumed to be the inner anhydride of the Bz.1- ylbenzanthrone of the formula: amino'benzanthrone-2-carboxylic acid, with a caustic soda solution of 5%, it is saponified go to the free acid, which may be isolated by acidifying the alkaline solution. Thebrownish red precipitate forms when recrystallized from nitrobenzene brown microscopical crystals melting at 278. The new compound is 5 soluble in concentrated sulfuric acid with a green color in cold caustic soda solution with H. g

a reddish violet, when warmed with a red- ,l a dish brown color, with ac1d condensmg agents 1n presence- 0,1.

- V. an indifferent diluent.v l e mp H p 4. Process for producing new condensat on- A mixture of 10 parts of B 1- jt -2- products of the benzanthrone series which I meth l-benzanthrone, 10 parts of finely process comprises treating Bz.1-n1-tro-'2-methde aluminium chloride and parts of ylbenzanthrone 0f the o trichloro benzene is boiled for about 6' hours as under reflux while well stirring- After coolmg-down the mass is diluted with water and the trichloro benzene is expelled with's'team; O: I

The product of reaction is filtered off and is boiled with a dilute h drochloric acid for in totally removing the a 'um salts. The

dyestufis thus obtained corresponds 1n its 1 properties to the dyestufi, describedin Example I, but dyes cotton less greenish tint. p )In order to obtain the new compound, de- 771th u l Sulfuric 4' 45 scriledhin 1tlie foregoing example and assugied g; testlmony h a our ,S1gna7 to t e z.1-am1no benzanthrone-2-car -ox- I lic acid, the dyestufi of Ex'ample'III may GEORG KALISQHER.

extracted with a dilute causticalkali solu- I HEINZ E tion-and the alkaline solution thus obtained" L AW "so ma i I p p v EMIL KRAUCH.

1. As new compounds condensationprodnets of the benz anthrone series, being when. gref toblack colored powders, ra'ctically 55' mso ub e in organic solvents, 'solu le in corn I centrated sulfuric acid to an olive solution forming with an alkalinesolution of hydro- 1 sulfitea reddish colored vat dyeing-cotton therefrom greenish to'bluish gre to black o0 shades of a very good fastness, w ch prodv I nets are substantially identical with thoseobtainable by treatin g 'Bz.1-nitro-2-methylb.en-

zanthrone with acid condensing agents.

2. Process for producing new condensation 06 products of the benzanthrone series which 

